Test Papers / Previous Question Papers of IGNOU CS13 Operating Systems December 1999

MCA (III Yr)
Term-End Examination

December, 1999

CS13 : Operating Systems

Time: 3 hours
Maximum Marks: 75

1. (a) Given a set of cooperating process, some of which produce" data items (producers) to be "consumed" by others (consumers), with possible disparity between production and consumption rates. Devise a synchronization protocol that allows both producers and consumers to operate concurrently at their respective service rates in such a way that produced items are consumed in the exact order in which they are produced (FIFO).

(b) Devise and explain the deadlock detection algorithm and explain its performance.

(c) Discuss the relative time and space complexities of the individual implementations of the message facility and propose an approach that you consider to be the best trade-off in terms of versatility versus performance.

2. (a) Threades are the convenient mechanisms for exploiting concurrency within an application. Discuss in support of the above statement.

(b) Explain the need for the process Control Block (PCB) fields.

(c) Discuss why Round Robin scheduling is often regarded as a fair scheduling discipline

3. (a) Explain how monitors provide structural data-abstraction in addition to concurrency control.

(b) Devise and explain Lamport's Bakery algorithm

4. (a) Devise and explain page-fault frequency algorithm.

(b) Explain the overall performance of static partitioned memory allocation with respect to principles of operation, swapping, relocation, protection and sharing.

5. (a) Explain the system programmer's view of the file system.

(b) List and interpret the security policies and mechanisms.

(c) Compare and contrast Bell-La Padula model and Lattice model of information flow.

6 (a) Discuss the implementation issues and considerations involved in processing and memory management in multiprocessor operating system.

(b) Explain why shared-bus multiprocessors are generally regarded as having limited scalability.